Underwater Wireless Optical Communication is a key enabling technology for future space-air-ground-sea integrated networks. However, UOWC faces critical hurdles from spatial randomness and stringent energy constraints. These challenges fundamentally limit network lifetime and sustainability. This paper develops a comprehensive stochastic geometry framework to perform a differential energy analysis of UOWC links.Instead of relying on simplified models, we employ a three-dimensional truncated Poisson point process to accurately capture the anisotropic nature of the underwater environment, specifically the disparity between horizontal spread and vertical depth. It incorporates a Lambertian emission pattern, random receiver positions and orientations, and a realistic channel model with extinction effects. Under this model, we derive a full suite of closed-form expressions for key performance indicators. These include the nearest-neighbor distance distribution, expected received power, SNR, and BER. A principal and counter-intuitive finding of our analysis is an offset-pointing strategy. This strategy involves intentionally misaligning the receiver by a deterministically optimal angle. This approach maximizes the integrated received power across the aperture, contrary to the conventional pursuit of perfect alignment. We formulate and solve an energy-efficiency optimization problem. Our results demonstrate that this strategy enhances system robustness and yields substantial performance gains. Simulation results validate our analytical models. They show that the optimal offset strategy can reduce the required transmit power by nearly 20\% to achieve a target BER. This reduction directly translates into extended network lifetime and higher total data throughput. These findings offer a new design paradigm for deploying robust, cost-effective, and sustainable UOWC networks.

翻译：水下无线光通信是未来空天地海一体化网络的关键使能技术。然而，UOWC面临着空间随机性和严格能量约束的关键障碍。这些挑战从根本上限制了网络寿命和可持续性。本文开发了一个全面的随机几何框架，对UOWC链路进行差异化能量分析。我们摒弃简化模型，采用三维截断泊松点过程来精确捕捉水下环境的各向异性特征，特别是水平扩散与垂直深度之间的差异。该框架融合了朗伯发射模式、随机接收器位置与朝向，以及包含消光效应的实际信道模型。在此模型下，我们推导出了一整套关键性能指标的闭式表达式，包括最近邻距离分布、期望接收功率、信噪比和误码率。我们分析的一个主要且反直觉的发现是偏置指向策略。该策略涉及有意地将接收器错开一个确定性最优角度。与传统追求完美对准的做法相反，这种方法旨在最大化孔径上的积分接收功率。我们构建并求解了一个能效优化问题。结果表明，该策略增强了系统鲁棒性并带来了显著的性能提升。仿真结果验证了我们的分析模型。结果表明，为实现目标误码率，最优偏置策略可将所需发射功率降低近20%。这种降低直接转化为延长的网络寿命和更高的总数据吞吐量。这些发现为部署鲁棒、经济高效且可持续的UOWC网络提供了新的设计范式。